Free rotating main propulsion shaft packing area resurfacing machine



July 17, 1962 D. c FINKES 3,044,224

FREE ROTATING MAIN PROPULSION SHAFT PACKING AREA RESURFACING MACHINE Filed May 15, 1961 INVENTOR. DA W0 6. Fl/VKES ATTOI? K David C. Finkes,

United States Fire 3,044,224 FREE @OTATING MAIN PRQPULSION SHAFT PACKING AREA RESURFACING MACHINE 1579 Tarrytown St., San Mateo, Calif. Filed May 15, 1961, Ser. No. 110,278

11 Claims. (Cl. 51241) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention pertains to rotary grinding machines of the type in which the grinding head rotates around the peripheral face of a stationary cylindrical work piece. More specifically it is a portable grinder that may be employed for resurfacing the journals of large ship propeller shaft stufiing boxes.

One of the hazards and costly maintenance problems of large ocean going ships results from leaky propeller shaft stuffing boxes. The condition frequently is caused by foreign matter in the packing which may tear the packing and cause the 'box to leak. A temporary expediency is to tighten the st-uffing box flange or gland but thismay aggravate the foreign matter condition and cause permanent scoring of the journal to a degree requiring resurfacing. A major repair of this nature usually requires placing the ship in dry dock and then removing the propeller shaft from the ship and transporting it to a machine shop having equipment large enough to swing the shaft. Such a repair operation is very costly but the period of time the ship is out of service is usually the most serious consideration.

By use of the proposed portable grinding machine, the stufling box on large propeller shafts can be resurfaced without disturbing the shaft other than removing the box flange and packing.

The general object of this invention is to provide a portable grinding machine for resurfacing damaged sections of circular shafts without rotating said shafts wherein said machine is sectionally assembled and rotatively supported on said shaft and employs the undamaged portions of said shaft as its circular guide for feeding an independently powered grinding head over said damaged section of said Circular shaft.

' Another object of this invention is to provide an apparatus for resurfacing the stuffing box journal of a large ships propeller shaft in its normally operating position.

Still another object is to provide a sectional mounting base for an independently powered circular grinding head capable of being rotatively mounted in an operable position on a propeller shaft and of swinging clear in the limited ship compartment space for resurfacing a portion of the shaft without removing the shaft from the ship.

Many refinements of the proposed machine may be provided such as an adjustable split cylinder to encircle the main propulsion shaft while held in a stationary condition in case the normal guide section is out of round and damaged beyond use for swinging the sectional mounting base during grinding operation. Means may also be pro vided for feed adjustments and control in addition to the specific structure size and mounting base for common class ship shaft sizes.

With these and other objects in view, as will hereinafter more fully appear, and which will be more particularly pointed out in the appended claims, reference is now made to the following description taken in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures there of and wherein:

FIG. 1 is a perspective view showing the portable circular grinder mounted on a shaft to be ground;

FIG. 2 is a blown-up perspective of the grinder ready for assembly;

FIG. 3 is a perspective of another species of the grinder mounted on a sleeve concentric with the shaft to be ground.

In detail, the shaft 13 FIG. 1 has a stuffing box section 17 which is to be resurfaced by grinding to remove eroded or scored packing areas. Under most conditions shaft 13- would be removed to a grinder or lathe where it may be swung or rotated for grinding. In the case of large shafts such as ship propeller shafts the problem of removing the shaft is enormous. However, it is sometimes possible to mount the grinding head on the shaft as an operable unit and rotate it around the shaft while maintaining the latter stationary in its normal position. The present invention was developed to meet this contingency and provide the necessary apparatus.

The gland or flange has been removed from the face 29 of stufiing box 30 thus exposing the stufling box section 17 of shaft 13 which is to be resurfaced. The grinder assembly illustrated in FIG. 2 comprises a mounting base 10 made in two sections 11 and 12, respectively, and held together by machine screws 36. The mounting base 10 is rotatively supported on shaft 13 by rollers 14, four on each face of the base. Said rollers are designed to ride on a section of the surface of shaft 13 which is smooth and concentric with the stuffing box surface 17. In case said surface is damaged or out of round a concentric split cylinder may be used such as 33- FIG. 3 which will be described in detail later in this specification.

The larger section 12 of the mounting base is designed for holding the independently driven motor 15 and grind ing head 16. A feed control device is also mounted on base section 12 which comprises a feed screw 20 screwed into a matching female thread passing through said section 12. A star wheel 19 is pinned to the feed screw 20 for rotating the screw in either direction. A feed roller 26 and an arcuate guide plate 23 are operatively held by a bracket 24 which is rotatively supported on the outboard end of the feed screw 20. The feed roller 26 is positioned for making rolling contact with flange face 29' of adjusting screws 31 and 32, the higher of grinder head 16 can be changed to provide the proper depth of cut or radial feed.

The axial travel and rotation'of the base 10 on shaft 13 is induced manually by force on the handles 18 spaced about the base 10. By directing the force diagonally, the feed roller 26 will be maintained in rolling contact with the flange face 29 as a result of the axial component and the grinding head 16 will circle the peripheral surface of the stufling box as a result of the tangential force. After one complete revolution of the base 10 about shaft,13, the star wheel 19 is rotated to gauge the exact amount of advance or axial feed of the wheel 16 for the next rotation of the base. These steps are repeated until a complete pass has been made over the section to be resurfaced.

One of the features of the design is the independent power driven grinder motor. FIG. 1, a fluid motor 15 .is supplied with power such as compressed air from a source 28 through a reel 27 and a flexible power connection or hose '21. The hose 21 In the structure shown in matic take-up reel 27 placed between the power source and base maintains the hose taut by taking up the slack. Although the motor could be electrically driven and the flexible connection 21 a wire power cable, the air motor as illustrated, is preferred. It has many advantages such as utilizing the exhaust from the motor for supplying fresh cool air to the operator. Still another advantage of the air motor is the elimination of the possibility of electrical shock which might occur from the electrical motor.

Another feature of the grinder structure is the counter balance plate 37 to compensate for the motor and feed screw weights added to the larger section 15 of the mounting base 10. In the particular design, the counter Weight 37 is provided with two adjusting slots 42 through which the handles 18 are inserted for screwing into the base section 11. By tightening or loosening the handles 18, the position of plate 37 can be circumferentially adjusted to provide the correct counter balance to base section 12.

A further refinement of the apparatus is shown in FIG. 3 wherein the shaft 13 is presumed to be so cut up that the rollers 14 would not track on a path concentric with the stufling box and, therefore, the resurface would not be a true circle. To overcome the trouble a split cylinder or sleeve 33 is provided and assembled on shaft 13. By means of a plurality of jacks 34 at each end of the sleeve, the sleeve is adjusted until it is concentric with the true shaft circumference. The peripheral surface of sleeve 33 is thus provided as a guide tract for rollers 14 in place of the peripheral surface of the shaft 13 as described above in reference to FIG. 1. Similar in principle to FIG. 1, FIG. 3 illustrates the sectional. mounting base 43 and the motor mounting channel 44. The feed screw 20 and star face 46 in place of the flange face 29, FIG. 1, in controlling the feed rate of grinding head 16. The same principle of the flexible power connection 21 being wound on fingers 22, prevails in each species. 7

Although the resurfacing abrasive wheel 16 has been termed a grinding head 16 it is appreciated that it may be a silicon carbide or resinoid grinding wheel or a rotary file or burr, selection being according tothe type of metal to be resurfaced.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is: a

1. In a portable grinding machine for grinding a circular shaft journal without rotating said shaft comprising a circular shaft nonrotatively supported and including a journal section to be ground, a split mounting base assembled on said shaft and rotatively supported on the peripheral surface of said shaft and adapted to move axially toward and away from said journal section on said surface, an independent power driven circular grinding head mounted on said base and positioned for operably contacting said journal section, manual means for rotating said assembled mounting base on said shaft and feeding said base axially along said shaft in relation to said journal, and a feed rate controlfor regulating the rate of axial advance of said base toward said journal.

2. The apparatus described in claim lwherein said split base assembly has a bore slightly larger than the outside diameter of said circular shaft, said base is rotatively mounted on said shaft on a plurality of rollers rotatively supported on the end faces of said base in periph eral contact with said shaft and in axial alignment therewith so that the entire base mounting said grinding head can be freely rotated around and axially fed toward and agvay from said journal on the peripheral surface of said s aft.

3. The apparatus described in claim 1 wherein said independent power driven circular grinding head is supalong said shaft.

4. The apparatus described in claim 3 wherein said circular grinding head is powered by a pneumatic motor and said flexible power connection is a pressure hose connecting said motor to a remote fluid pressure power source.

5. The apparatus described in claim 1 wherein the means for rotating said base on said shaft and axially moving the same toward and away from said journal comprises a plurality of handles projecting radially outward from said base and respectively spaced about said base within easy reach of an operator so that continuous manual operation both rotatively and axially is feasible.

6. The apparatus described in claim 1 wherein the means for moving said base axially on said shaft in relation to said journal within controlled limitations comprises a stuffing box for said journal provided with a flanged end face, a feed screw threaded into said split base and provided with means at its outboard end for guided operational contact with said flanged end face, means for rotating said feed screw thereby controlling the distance between the split base and said stuffing box flange face and in turn the axial operating position of the grinding head on said journal surface.

-7. The apparatus described in claim 6 wherein the means at the feed screws outboard end for guided operational contact with said flanged end face comprises a bracket mounted on the end of said feed screw and free to rotate thereon, a feed roller positioned for making operational rolling contact with said flanged end face and an arcuate guide plate fixed to said bracket and maintained in frictional sliding contact with the internal cylindrical surface of said stuffing box for guiding the feed roller along its circular path on said flange face.

8. In a portable circular grinding machine for stationary shafts comprising a circular shaft having a journal portion to be ground, a sectional mounting base having a central bore slightly larger than the diameter of said circular shaft, said base being assembled on said shaft and equipped with means for providing concentric rotation on said shaft, an independently powered grinding head mounted on said base and adapted for making grinding contact with said journal, and means for manually rotating said base on said shaft and advancing and retracting the grinding head axially over said journal, said independently powered grinding head is connected to a remote power source through a flexible connection and the sectional mounting base is provided with means for concurrently winding or unwinding said flexible connection during operation.

9. In a portable circular grinding machine for circular grinding a section of a shaft without rotating said shaft comprising a circular shaft nonrotatively supported and including a journal section to be ground, a sectional cylindrical sleeve assembled on said shaft, means for mounting said sleeve concentric with said shaft, a sectional mounting base rotatively mounted on said sleeve, an independently powered grinding head mounted on said base and adapted for making grinding contact with said journal, and means for rotating said base on said sleeve and advancing and retracting the grinding head axially over said journal.

10. The apparatus set forth in claim 9 wherein said independently powered grinding head is connected to a remote power source through a flexible connection and the sectional mounting base is provided with means for winding and unwinding said flexible connection during operation.

11. In a portable circular grinding machine for circular grinding a section of a shaft without rotating said shaft comprising a circular shaft nonrotatively supported and including a journal section to be ground, a sectional cylindrical sleeve assembled on said shaft, means for mounting said sleeve concentric with said shaft, a sectional mounting base rotatively mounted on said sleeve, an independently powered grinding head mounted on said base and adapted for making grinding contact with said journal, means for rotating said base on said sleeve and advancing and retracting the grinding head axially over said journal, a feed screw threaded into said sectional mounting base and provided with means at its outboard end for operational contact with the end face of said cylindrical sleeve, and means for rotating said the axial operating position of the grinding'head on'the i I journal section surface to be ground.

References Cited in the file ofthis patent I UNITED STATES PATENTS 2,257,619 Prill "Sept.-30 1941 2,698,505 Marsh Jan. 4, 1955 r 2,755,609 Sylvester July 24, 1956,

FOREIGN PATENTS 327,951 Germany Oct. 19, 1920 

